Comment by criddell
7 hours ago
> Speed-limits typically remain grandfathered in at their original value
That depends on where you are. In Texas, state highway speed limits are determined though a traffic study[1]. The monitor traffic for a while, then set the limit to the 85th percentile.
People can use this to get out of speeding tickets. If you find that it's been a long time since a speed study was done on the road you were on, the judge might throw the ticket out.
There are some hard limits though. For example, the maximum speed limit that can be set on a road is 85 mph.
[1]: https://www.txdot.gov/safety/driving-laws/speed-limits/speed...
In other words, 15% of people are ALWAYS speeding, by definition.
So with perfect enforcement (punish everyone over the threshold), how do you enable an 85th percentile rule?
> 15% of people are ALWAYS speeding, by definition
Not necessarily. If the data is heavily clustered around a single value, the percentile collapses to that number.